textproduct: Rapid City

KEY MESSAGES

- Warm and mainly dry continues Sunday with isolated showers

- Critical fire weather conditions for parts of the area through Monday, mainly along and south of I90

- Upper trough will bring some precip chances to the region Tue with additional chances toward the end of the week

UPDATE

Issued at 1100 PM MDT Sat Apr 11 2026

Upper air southwest flow continues aloft tonight, with a strong shortwave now crossing NE WY. Weak cool front is crossing the CWA at this time...with gusty westerly winds increasing behind the front. Surface obs show winds already increasing across NE through the Black Hills into the northern/eastern foothills and adjacent plains. Temps on Sunday will not be quite as warm as today's was, but still well above average with highs in the 70s to near 80. These breezy westerly winds will continue through the day...then decrease by sunset. Another shortwave will cross the region Sunday night, bringing isolated showers to portions of the area. Most of it will be virga, with little to no QPF. A weak trough will cross the region for the first half of the week, bringing low chances of showers and cooler (but still above average) temperatures.

DISCUSSION

(This Afternoon Through Friday) Issued at 1126 AM MDT Sat Apr 11 2026

Upper trough will continue to dig into the western CONUS, with continued downstream ridging to the east. This will support warm and mainly dry weather through Monday. Although a few isolated showers will be possible tonight as a lead impulse crosses the area. Dry SW flow is ongoing across the SW FA. As mixing and pressure falls continue, expect flow to increase this afternoon across the southern half of the FA. A lead impulse will shift the lee-side trough into the FA later in the afternoon/evening. Enough high level moisture and instability will be in place to force isolated very high based showers and perhaps a few TS, esp over NE WY and far SW SD. Gusty winds would be expected with any convection that does develop given inverted V profiles in a deeply mixed BL. Shower activity will carry northeast through the evening. Sfc trough will push into the area and stall as the main upper trough pushes east into the Rockies. This will support another mild day across the region Sunday with highs in the 70s, a few low 80s in scentral SD. Dry SW flow can be expected due to continued very dry BL conditions. This process will repeat Monday as the cool front will be delayed by the next sfc low ejecting into region. Cool front starts to progress east into the area Monday night with increasing upper level moisture. This could support a few showers by afternoon into the overnight hours across the NW third. As the main upper trough moves across the region Tues, slightly better coverage is anticipated, but less than previous model runs as the bulk of moisture remains south and east of the FA. Hence trended pops down Tue, with Wed likely dry. Mild weather will continue through Thur as WAA ensues ahead of the next upper trough which will advect ESE in westerly flow out of the Pac NW. This system will bring another round of precip chances to the region toward the end of the week, although confidence in chances and amounts remains low given the time period.

AVIATION

(For the 12Z TAFS Through 12Z Monday Morning) Issued At 515 AM MDT Sun Apr 12 2026

VFR conditions are expected through the valid forecast period. West winds will continue to be breezy across the area today. Isolated sprinkles/showers late this afternoon and evening from the Black Hills west could bring brief local MVFR visibility, along with erratic wind gusts to 50 mph.

FIRE WEATHER

Issued At 1100 PM MDT Sat Apr 11 2026

Gusty southwest winds, very dry air, and lack of appreciable green up will support critical fire weather conditions through Monday over portions of northeast WY and western SD, mainly along and south of I90. A Red Flag Warning remains in effect through Sunday; however, critical fire weather conditions are likely again Monday as dry SW flow continues along and south of I90 with another extension of the Red Flag Warning likely needed. A low pressure system will move into the region early next week, potentially bringing some precipitation to the area, although rain chances are low.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning until 9 PM MDT this evening for SDZ320>322- 324>326-329-332. Red Flag Warning from 11 AM MDT /noon CDT/ this morning to 9 PM MDT /10 PM CDT/ this evening for SDZ331-333>335. WY...Red Flag Warning until 9 PM MDT this evening for WYZ314-315-317.